libvirt/src/util/virxml.h
Peter Krempa 45a61cbf68 util: xml: Fix confusing semantics of VIR_XML_PROP_OPTIONAL flag
The new enum helpers use a set of flags to modify their behaviour, but
the declared set of flags is semantically confusing:

 typedef enum {
     VIR_XML_PROP_OPTIONAL = 0, /* Attribute may be absent */
     VIR_XML_PROP_REQUIRED = 1 << 0, /* Attribute may not be absent */

Since VIR_XML_PROP_OPTIONAL is declared as 0 any other flag shadows it
and makes it impossible to detect. The functions are not able to detect
a semantic nonsense of VIR_XML_PROP_OPTIONAL | VIR_XML_PROP_REQUIRED and
it's a perfectly valid statement for the compilers.

In general having two flags to do the same boolean don't make sense and
the implementation doesn't fix any shortcomings either.

To prevent mistakes, rename VIR_XML_PROP_OPTIONAL to VIR_XML_PROP_NONE,
so that there's always an enum value used with the calls but it doesn't
imply that the flag makes the property optional when the actual value is
0.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2021-04-21 10:32:17 +02:00

378 lines
11 KiB
C

/*
* virxml.h: helper APIs for dealing with XML documents
*
* Copyright (C) 2005, 2007-2012 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#pragma once
#include "internal.h"
#include <libxml/parser.h>
#include <libxml/tree.h>
#include <libxml/xpath.h>
#include <libxml/relaxng.h>
#include "virbuffer.h"
#include "virenum.h"
xmlXPathContextPtr virXMLXPathContextNew(xmlDocPtr xml)
G_GNUC_WARN_UNUSED_RESULT;
typedef enum {
VIR_XML_PROP_NONE = 0,
VIR_XML_PROP_REQUIRED = 1 << 0, /* Attribute may not be absent */
VIR_XML_PROP_NONZERO = 1 << 1, /* Attribute may not be zero */
} virXMLPropFlags;
int
virXPathBoolean(const char *xpath,
xmlXPathContextPtr ctxt);
char *
virXPathString(const char *xpath,
xmlXPathContextPtr ctxt);
char *
virXPathStringLimit(const char *xpath,
size_t maxlen,
xmlXPathContextPtr ctxt);
int
virXPathNumber(const char *xpath,
xmlXPathContextPtr ctxt,
double *value);
int
virXPathInt(const char *xpath,
xmlXPathContextPtr ctxt,
int *value);
int
virXPathUInt(const char *xpath,
xmlXPathContextPtr ctxt,
unsigned int *value);
int
virXPathLong(const char *xpath,
xmlXPathContextPtr ctxt,
long *value);
int
virXPathULong(const char *xpath,
xmlXPathContextPtr ctxt,
unsigned long *value);
int
virXPathULongLong(const char *xpath,
xmlXPathContextPtr ctxt,
unsigned long long *value);
int
virXPathLongLong(const char *xpath,
xmlXPathContextPtr ctxt,
long long *value);
int
virXPathLongHex(const char *xpath,
xmlXPathContextPtr ctxt,
long *value);
int
virXPathULongHex(const char *xpath,
xmlXPathContextPtr ctxt,
unsigned long *value);
xmlNodePtr
virXPathNode(const char *xpath,
xmlXPathContextPtr ctxt);
int
virXPathNodeSet(const char *xpath,
xmlXPathContextPtr ctxt,
xmlNodePtr **list);
char *
virXMLPropString(xmlNodePtr node,
const char *name);
char *
virXMLPropStringLimit(xmlNodePtr node,
const char *name,
size_t maxlen);
char *
virXMLNodeContentString(xmlNodePtr node);
int
virXMLPropTristateBool(xmlNodePtr node,
const char *name,
virXMLPropFlags flags,
virTristateBool *result)
ATTRIBUTE_NONNULL(0) ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(3);
int
virXMLPropTristateSwitch(xmlNodePtr node,
const char *name,
virXMLPropFlags flags,
virTristateSwitch *result)
ATTRIBUTE_NONNULL(0) ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(3);
int
virXMLPropInt(xmlNodePtr node,
const char *name,
int base,
virXMLPropFlags flags,
int *result)
ATTRIBUTE_NONNULL(0) ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(4);
int
virXMLPropUInt(xmlNodePtr node,
const char* name,
int base,
virXMLPropFlags flags,
unsigned int *result)
ATTRIBUTE_NONNULL(0) ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(4);
int
virXMLPropEnum(xmlNodePtr node,
const char* name,
int (*strToInt)(const char*),
virXMLPropFlags flags,
unsigned int *result)
ATTRIBUTE_NONNULL(0) ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2)
ATTRIBUTE_NONNULL(4);
/* Internal function; prefer the macros below. */
xmlDocPtr
virXMLParseHelper(int domcode,
const char *filename,
const char *xmlStr,
const char *url,
const char *rootelement,
xmlXPathContextPtr *ctxt);
const char *
virXMLPickShellSafeComment(const char *str1,
const char *str2);
/**
* virXMLParse:
* @filename: file to parse, or NULL for string parsing
* @xmlStr: if @filename is NULL, a string to parse
* @url: if @filename is NULL, an optional filename to attribute the parse to
*
* Parse xml from either a file or a string.
*
* Return the parsed document object, or NULL on failure.
*/
#define virXMLParse(filename, xmlStr, url) \
virXMLParseHelper(VIR_FROM_THIS, filename, xmlStr, url, NULL, NULL)
/**
* virXMLParseString:
* @xmlStr: a string to parse
* @url: an optional filename to attribute the parse to
*
* Parse xml from a string.
*
* Return the parsed document object, or NULL on failure.
*/
#define virXMLParseString(xmlStr, url) \
virXMLParseHelper(VIR_FROM_THIS, NULL, xmlStr, url, NULL, NULL)
/**
* virXMLParseFile:
* @filename: file to parse
*
* Parse xml from a file.
*
* Return the parsed document object, or NULL on failure.
*/
#define virXMLParseFile(filename) \
virXMLParseHelper(VIR_FROM_THIS, filename, NULL, NULL, NULL, NULL)
/**
* virXMLParseCtxt:
* @filename: file to parse, or NULL for string parsing
* @xmlStr: if @filename is NULL, a string to parse
* @url: if @filename is NULL, an optional filename to attribute the parse to
* @pctxt: if non-NULL, populate with a new context object on success,
* with (*pctxt)->node pre-set to the root node
*
* Parse xml from either a file or a string.
*
* Return the parsed document object, or NULL on failure.
*/
#define virXMLParseCtxt(filename, xmlStr, url, pctxt) \
virXMLParseHelper(VIR_FROM_THIS, filename, xmlStr, url, NULL, pctxt)
/**
* virXMLParseStringCtxt:
* @xmlStr: a string to parse
* @url: an optional filename to attribute the parse to
* @pctxt: if non-NULL, populate with a new context object on success,
* with (*pctxt)->node pre-set to the root node
*
* Parse xml from a string.
*
* Return the parsed document object, or NULL on failure.
*/
#define virXMLParseStringCtxt(xmlStr, url, pctxt) \
virXMLParseHelper(VIR_FROM_THIS, NULL, xmlStr, url, NULL, pctxt)
/* virXMLParseStringCtxtRoot is same as above, except it also validates root node name */
#define virXMLParseStringCtxtRoot(xmlStr, url, rootnode, pctxt) \
virXMLParseHelper(VIR_FROM_THIS, NULL, xmlStr, url, rootnode, pctxt)
/**
* virXMLParseFileCtxt:
* @filename: file to parse
* @pctxt: if non-NULL, populate with a new context object on success,
* with (*pctxt)->node pre-set to the root node
*
* Parse xml from a file.
*
* Return the parsed document object, or NULL on failure.
*/
#define virXMLParseFileCtxt(filename, pctxt) \
virXMLParseHelper(VIR_FROM_THIS, filename, NULL, NULL, NULL, pctxt)
int
virXMLSaveFile(const char *path,
const char *warnName,
const char *warnCommand,
const char *xml);
char *
virXMLNodeToString(xmlDocPtr doc,
xmlNodePtr node);
bool
virXMLNodeNameEqual(xmlNodePtr node,
const char *name);
xmlNodePtr
virXMLFindChildNodeByNs(xmlNodePtr root,
const char *uri);
int
virXMLExtractNamespaceXML(xmlNodePtr root,
const char *uri,
char **doc);
int
virXMLInjectNamespace(xmlNodePtr node,
const char *uri,
const char *key);
void
virXMLNodeSanitizeNamespaces(xmlNodePtr node);
int
virXMLCheckIllegalChars(const char *nodeName,
const char *str,
const char *illegal);
struct _virXMLValidator {
xmlRelaxNGParserCtxtPtr rngParser;
xmlRelaxNGPtr rng;
xmlRelaxNGValidCtxtPtr rngValid;
virBuffer buf;
char *schemafile;
};
typedef struct _virXMLValidator virXMLValidator;
virXMLValidator *
virXMLValidatorInit(const char *schemafile);
int
virXMLValidatorValidate(virXMLValidator *validator,
xmlDocPtr doc);
int
virXMLValidateAgainstSchema(const char *schemafile,
xmlDocPtr xml);
int
virXMLValidateNodeAgainstSchema(const char *schemafile,
xmlNodePtr node);
void
virXMLValidatorFree(virXMLValidator *validator);
G_DEFINE_AUTOPTR_CLEANUP_FUNC(virXMLValidator, virXMLValidatorFree);
void
virXMLFormatElement(virBuffer *buf,
const char *name,
virBuffer *attrBuf,
virBuffer *childBuf);
struct _virXPathContextNodeSave {
xmlXPathContextPtr ctxt;
xmlNodePtr node;
};
typedef struct _virXPathContextNodeSave virXPathContextNodeSave;
void
virXPathContextNodeRestore(virXPathContextNodeSave *save);
G_DEFINE_AUTO_CLEANUP_CLEAR_FUNC(virXPathContextNodeSave, virXPathContextNodeRestore);
/**
* VIR_XPATH_NODE_AUTORESTORE:
* @ctxt: XML XPath context pointer
*
* This macro ensures that when the scope where it's used ends, @ctxt's current
* node pointer is reset to the original value when this macro was used.
*/
#define VIR_XPATH_NODE_AUTORESTORE(_ctxt) \
VIR_WARNINGS_NO_UNUSED_VARIABLE \
g_auto(virXPathContextNodeSave) _ctxt ## CtxtSave = { .ctxt = _ctxt,\
.node = _ctxt->node}; \
VIR_WARNINGS_RESET
G_DEFINE_AUTOPTR_CLEANUP_FUNC(xmlDoc, xmlFreeDoc);
G_DEFINE_AUTOPTR_CLEANUP_FUNC(xmlXPathContext, xmlXPathFreeContext);
G_DEFINE_AUTOPTR_CLEANUP_FUNC(xmlBuffer, xmlBufferFree);
G_DEFINE_AUTOPTR_CLEANUP_FUNC(xmlNode, xmlFreeNode);
G_DEFINE_AUTOPTR_CLEANUP_FUNC(xmlParserCtxt, xmlFreeParserCtxt);
typedef int (*virXMLNamespaceParse)(xmlXPathContextPtr ctxt,
void **nsdata);
typedef void (*virXMLNamespaceFree)(void *nsdata);
typedef int (*virXMLNamespaceFormat)(virBuffer *buf,
void *nsdata);
typedef const char *(*virXMLNamespaceHref)(void);
struct _virXMLNamespace {
virXMLNamespaceParse parse;
virXMLNamespaceFree free;
virXMLNamespaceFormat format;
const char *prefix;
const char *uri;
};
typedef struct _virXMLNamespace virXMLNamespace;
void
virXMLNamespaceFormatNS(virBuffer *buf,
virXMLNamespace const *ns);
int
virXMLNamespaceRegister(xmlXPathContextPtr ctxt,
virXMLNamespace const *ns);
int
virParseScaledValue(const char *xpath,
const char *units_xpath,
xmlXPathContextPtr ctxt,
unsigned long long *val,
unsigned long long scale,
unsigned long long max,
bool required);
xmlBufferPtr
virXMLBufferCreate(void);
xmlNodePtr
virXMLNewNode(xmlNsPtr ns,
const char *name);